Composite pane having electrically conductive coating for a head-up display

Abstract

A composite pane for a head-up display is described. The composite pane has an upper edge and a lower edge, at least including an outer pane and an inner pane. The outer pane and the inner pane are joined to one another via a thermoplastic intermediate layer. A transparent, electrically conductive coating on the surface of the inner pane faces the intermediate layer. The thickness of the intermediate layer is variable at least in sections in the vertical course between the lower edge and the upper edge. The inner pane has a thickness less than 1.6 mm, the outer pane has a thickness of 2.1 mm to 4.5 mm, and the total thickness (d) of the composite pane is at least 4.4 mm.

The invention claimed is: 
     
       1. A composite pane for a head-up display, comprising:
 an upper edge; 
 a lower edge; 
 an outer pane; 
 an inner pane,
 wherein the outer pane and the inner pane are joined to one another via a thermoplastic intermediate layer; and 
 
 a transparent, electrically conductive coating on the surface of the inner pane facing the intermediate layer,
 wherein the thickness of the intermediate layer is variable at least in sections in the vertical course between the lower edge and the upper edge, and 
 wherein the inner pane has a thickness less than 1.6 mm, the outer pane has a thickness of 2.1 mm to 4.5 mm, and a total thickness of the composite pane is at least 4.4 mm. 
 
 
     
     
       2. The composite pane according to  claim 1 , wherein the composite pane is a vehicle windshield. 
     
     
       3. The composite pane according to  claim 1 , wherein the total thickness is from 4.4 mm to 6.0 mm. 
     
     
       4. The composite pane according to  claim 1 , wherein the total thickness is from 4.4 mm to 5.5 mm. 
     
     
       5. The composite pane according to  claim 1 , wherein the thickness of the inner pane is from 0.4 mm to 1.5 mm. 
     
     
       6. The composite pane according to  claim 1 , wherein the thickness of the inner pane is from 0.7 mm to 1.1 mm. 
     
     
       7. The composite pane according to  claim 1 , wherein the thickness of the outer pane is from 2.5 mm to 3.5 mm. 
     
     
       8. The composite pane according to  claim 1 , wherein the minimum thickness of the intermediate layer is from 0.4 mm to 1.5 mm. 
     
     
       9. The composite pane according to  claim 1 , wherein the minimum thickness of the intermediate layer is from 0.5 mm to 1.0 mm. 
     
     
       10. The composite pane according to  claim 1 , wherein the intermediate layer has a wedge angle from 0.2 mrad to 1 mrad. 
     
     
       11. The composite pane according to  claim 1 , wherein the intermediate layer has a wedge angle from 0.3 mrad to 0.7 mrad. 
     
     
       12. The composite pane according to  claim 1 , wherein the intermediate layer has a wedge angle from 0.4 mrad to 0.5 mrad. 
     
     
       13. The composite pane according to  claim 1 , wherein the outer pane and/or the inner pane are made of glass. 
     
     
       14. The composite pane according to  claim 1 , wherein the outer pane and/or the inner pane are made of soda lime glass. 
     
     
       15. The composite pane according to  claim 1 , wherein the outer pane and the inner pane are made of glass. 
     
     
       16. The composite pane according to  claim 1 , wherein the outer pane and the inner pane are made of soda lime glass. 
     
     
       17. The composite pane according to  claim 1 , wherein the intermediate layer contains at least polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU), or mixtures or copolymers or derivatives thereof. 
     
     
       18. The composite pane according to  claim 1 , wherein the electrically conductive coating includes at least one electrically conductive layer, and wherein the at least one electrically conductive layer contains silver. 
     
     
       19. A projection arrangement for a head-up display, comprising:
 a composite pane according to  claim 1 ; and 
 a projector,
 wherein the projector is aimed at a region of the composite pane, and 
 wherein the thickness of the intermediate layer is variable at least in the region of the composite pane. 
 
 
     
     
       20. A motor vehicle, comprising:
 a windshield,
 wherein the windshield comprises the composite pane according to  claim 1 , and 
 wherein the composite pane further comprises a projection surface for a head-up display. 
 
 
     
     
       21. The motor vehicle according to  claim 20 , wherein the motor vehicle is a passenger car. 
     
     
       22. A method for producing a composite pane for a head-up display having an upper edge and a lower edge, comprising:
 providing an inner pane having a thickness less than 1.6 mm; 
 providing a surface of the inner pane with a transparent, electrically conductive coating; 
 providing a thermoplastic intermediate layer having a thickness, wherein the thickness is variable at least in sections in the course between two opposite edges; 
 arranging the thermoplastic intermediate layer between an outer pane and the inner pane, wherein the surface of the inner pane provided with the transparent, electrically conductive coating faces the intermediate layer and the thermoplastic intermediate layer are oriented in a direction from the lower edge to the upper edge, and wherein a total thickness of the composite pane is at least 4.0 mm; and 
 joining together the inner pane and the outer pane by lamination. 
 
     
     
       23. The method for producing a composite pane according to  claim 22 , wherein the electrically conductive coating is applied by physical vapor deposition (PVD). 
     
     
       24. The method for producing a composite pane according to  claim 22 , wherein the electrically conductive coating is applied by cathodic sputtering. 
     
     
       25. The method for producing a composite pane according to  claim 22 , wherein the electrically conductive coating is applied by magnetic field-enhanced cathodic sputtering.